STR Holdings, Inc. (NYSE: STRI) and the Fraunhofer USA Center for Sustainable Energy Systems (Fraunhofer CSE) will present a jointly-authored technical paper at the 27 th European Photovoltaic Solar Energy Conference and Exhibition in Frankfurt Germany during the week of September 24, 2012. The paper will highlight a 1% relative power gain when using STR PHOTOCAP® 15505P HLT™, as confirmed by independent module testing conducted by Fraunhofer CSE. STR’s High Light Transmission (HLT) technology boosts the total spectral transmission of the encapsulant by delivering more light to the PV device, yielding higher power output compared to non-HLT products. The paper will draw from a study focused on three different types of PV cells and the associated power gain as laminated and after 1,000 hours of damp heat testing. The study shows that the power gain is consistently achieved for all subject cells and is retained after damp heat testing. Unlike many competing products, STR HLT™ encapsulants still contain UV stabilization systems to protect the polymer from long-term damage by high-energy photons. “HLT is a commercial technology platform applicable to any existing or new EVA encapsulant that we produce,” said Robert S. Yorgensen, STR’s President and Chief Executive Officer. “This is the first commercial product release flowing from our increased investment in research and development and we look forward to many more.” Web links http://cse.fraunhofer.org http://www.strsolar.com http://www.photovoltaic-conference.com About STR Holdings, Inc. STR Holdings, Inc. is a leading global provider of high quality, superior performance encapsulants to the photovoltaic module industry. Further information about STR Holdings, Inc. can be obtained via the Company’s website at www.strholdings.com. Safe Harbor Statement This press release and any oral statement made in respect of the information in this press release contain forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements are subject to inherent risks and uncertainties. These forward-looking statements present the Company’s current expectations and projections relating to its financial condition, results of operations, plans, objectives, future performance and business and are based upon assumptions that the Company has made in light of its industry experience and perceptions of historical trends, current conditions, expected future developments and other factors management believes are appropriate under the circumstances. However, these forward-looking statements are not guarantees of future performance or financial or operating results. The Company undertakes no obligation to publicly update any forward-looking statements contained in this release, whether as a result of new information, future developments or otherwise, except as may be required by law.